Silicone rubber compositions of the addition curing type undergo crosslinking through hydrosilylation reaction represented by the following scheme as elementary reaction, converting into elastomers. ##STR1##
To control this reaction in order to insure a pot life or shelf life, a typical prior art practice uses ethynyl group-bearing compounds as shown below. ##STR2##
These compounds, however, are incompatible with fluorosilicones and perfluoropolymers having high fluorine contents and can introduce separation or non-uniformity into the reaction system.